Plug-micrometer



L..G. ILIFF.

PLUG MICROMETER. APPLICATION FILED own. 1920.

1,396, 1 1 7', Patented Nov. 8, 1921.

J #9 l I v WIT f I y 'INVENTOR. M 97 BY ATTORNEY;-

PATENT OFFICE.

LLOYD G. ILIFF, OF KANSAS CITY, MISSOURI.

PLUG-MICROMETER.

Specification of Letters Patent.

Patented Nov. 8, 1921.

Application filed December 24, 1920. Serial No. 433,049.

To all whom it may concern.-

Be it known that I, LLOYD G. ILIFF, a citizen of the United States, residing at Kansas City, in the county of Jackson and State of issouri, have invented a certain new and useful Improvement in Plug-Micrometers, of which the following is a specification.

My invention relates to improvements in plug micrometers.

The object of my invention is to provide a micrometer with which may be accurately measured the diameters of holes too small to admit the ordinary calipers.

The novel features of my invention are hereinafter fully described and claimed.

In the accompanyingdrawing which illustrates the preferred embodiment of my inventlon, v

Figure l is a central, longitudinal sectional view of my improved plug micrometer.

Fig. 2 is a side elevation of the' same.

Fig. 3 is a front end view of the same.

Fig. 4is a vertical sectional view of the slotted front cap. 7

Fig. 5 is a cross section on the line 5 of Fig. 1.

Fig. 6 is a top view of a portion of the measuring plug. a

' Fig. 7 is an enlarged fragmental portion of the longitudinall graduated cylinder.

Similar reference characters designate similar parts in the different views.

1 designates an elongated measuring member comprising, preferably, a plug having a relatively thin flat tapering portion 2, which may be a central longitudinal section of a cone, and which is adapted to have its smaller end inserted into a hole which is to be measured. .The plug 1 has a central longitudinal shank 3 of cylindrical form, which has revolubly mounted on it an externally threaded'sleeve 4 on which is fitted the inner end of ahollow cylinder 5, the outer end of which is fitted revolubly on the plug 1, said outer end being externally screw threadedand having fitted thereon an internally threaded cap 6, which is held in the position, to which it may be adjusted, by a lock nut 7. The cap 6 in its front'end has a slot 8 in which is slidably fitted the fiat tapering portion 20f the plug.

The inner end of the cylinder 5 has a longitudinal, central, slightly tapering, internally and externally. threaded extension 9, fitted to the threaded sleeve 4 and having one or more longitudinal'slots l0, and having mounted on it a nut 11 arranged to press the extension 9 against the sleeve 4 to prevent accidental turning of the cylinder 5.

The exterior of the cylinder 5 has a longitudinal row of graduations 12, Figs. 1 and 7, each of which represents one-tenth of an inch in transverse diameter on the tapering portion 2, the thread of the sleeve 5 being fifty to the inch, and the taper of the portion 2 being six inches to the foot. Between the graduations 12 are subdivisions 12, Fig. 7, each representing one-hundredth of an inch in transverse diameter on the tapering portion 2.

A barrel 13 has one end revolubly fitted on the cylinder 5. The other end of the barrel 13 is closed and has a central hole 14 through which the sleeve 4 extends. Two nuts 15 and 16 are fitted to the sleeve 4 and bear against opposite sides of the closed end of the barrel 13. By adjusting the nuts 15 and 16, the barrel 13 may be adjusted on the sleeve 4. The left end, Fig. 1, of the shank 3 is threaded and has fitted thereon two nuts 17 and 18, the latter having a bearing against the nut 15, and the forward end of the sleeve 4 having a bearing against the enlarged portion of the plug 1. Endwise move ment of the sleeve 4 on the shank 3 is thus prevented.

The barrel 13 at its right end, Figs. 1 and 2, tapers to a thin edge arranged to cooperate with the graduations 12 and 12. Said tapering portlon 19 is circumferentially divided into numbered graduations 20, ten in number, the spaces between the graduations 20 being subdivided into ten graduations each.

The numbered graduations 20 represent each one thousandth, and the subdivisions designated by 21 representing each one ten thousandth of an inch transverse diameter on the tapering portion 2 and double thls amount in longitudinal measurement on the tapering portion. The graduations on the tapering portion 19 are arranged to pooperate with a graduation 22 on the cylinder, Fig. 2.

In the left end of the shank 3, Fig. 1, is provided a longitudinal, central, threaded hole in which is fitted a screw 23 on which is rotatably mounted a peripherally mllled cyinder 24 having at its inner end one or more longitudinal holes in which are respectively mounted helical springs 25 whlch respectively bear against balls 26, WhlCh are r 7 measured so as to hear at opposite sides against opposite sides of the hole. The barrel 13 is then turned, preferably by means of the milledcylinder 2e, so as to turn the sleevee, to which the barrel 13 is clamped I by means of the nuts 15 and16, in a direction such that the sleeve 4: will advance the graduated cylinder 5 and cap 6 until the latter bears against the object having the hole to be measured. When the cap 6 bears against said object and the tapering portion Zis fitted in the hole in said object, the reading on the micrometer istaken in-the usual manner.

In the form' shown, the 'graduations 12.

cover a longitudinal length representing .three lineal inches, this space beingsubdivided into fifteen numbered graduations 12 which represent one hundred and fifty one hundredths 01 an inch, or one and a half inches in transverse diameter on the tapering portion 2. This instrument could, therefore, be'utilized for measuring diameters up toone and a half inches. WVith this construction, the threads of the sleeve 4:, being fifty to theinch, the longitudinal length of the tapering portion 2 from its point to its Y widest diameter would be three inches, the same as the distance between the graduations zero and fifteen on the cylinder 5. The V thin fiat portionyflof'the measuring memher 1 being fitted in the elongated slot 8, holds the measuring member from turning in the cap 6. It'a-lso affords a means of measuring different diameters of a hole, other than circular, such as an elliptical or rectangular hole, Which two functions could not be effected were the tapering portion circular instead of flat in cross section.

' I do not limit my invention to the structure shown and described, as many modifications, within the scope of the appended claims, may be made without departing from the spirit of my invention.

What I claim is 1. In a micrometer, a member having a tapering measuring endportion, an externally threaded sleeve rotatable on'said member'and held from longitudinal movement thereon, an elongated member provided with a longitudinal row of graduations and having "threaded engagement with said sleeve, and a barrel. member movable with said as set forth.

ber engaging said holding means adjacent sleeveiand encircling said graduated member and having a circumferentially graduated end portion arranged to cooperate with the said longitudinal graduations, substantially 7 O 2. In a micrometer, a member having a fiat relatively thin tapering end portion adapted for insertion into a hole to'be measured, an externally threaded sleeve rotatable onsaicl member and bearing at one end against said member, an elongated memberprovided with a longitudinal row or gra-uduations and having threaded engage ment with said sleeve, means for holding the first named member from turning but permitting it to move longitudinally in the graduated member, a barrel member having means for adjustment longitudinally on said sleeve and for being clamped to the sleeve and encircling said graduated member and having a circumferentially graduated end portion arranged to cooperate with said longitudinal graduations, and longitudinally adjustable means on said first named memto the other end of said sleeve, substantially as set forth. V 1 J 3. In a micrometer, a measuring plug having a tapering-end portion adapted to Y be extended into and to measure the diameter of a hole, anexternally threaded sleeve revoluble on said plug, an elongated member provided with a longitudinal row. of graduationsand in which the plug is-longi- 7 tudinally slidable, a cap rigidly attached to one end of the graduated member having a slot through which the tapering portion of the plug extends and which holds the plug from turning in the graduated member, and 5 a member movable with said sleeve and ar- 10 ranged to indicate said ggraduations, substantially as set forth. 1 p

4. In a "micrometer, a measuring plug having a flat relatively" thintapering end portion, an externally threaded sleeve rotatable and said plug, an elognate'd member provided'witha longitudinalrow of graduations and having threaded engagement with saidsleev'e and in which theaplug is longitudinally slidable, a'cap on one end of said graduated member having a slot in which said tapering :portion of the plug is longitu'dinally slidably fitted, a barrel member encircling the-graduated member and having circumferentially graduated end por- V tion'arranged to cooperate with the graduations on the graduated member and movable with said sleeve, and means for holding the sleeve against longitudinal movement on said plug, substantiallyassetforth;

5'. Ina micrometer, 'a'n'elongatedmember having a :relatively thin fiat tapering end portion,a supporting member having a slot in which said tapering :portion is longitudinallyslidably fitted, and "means cooper 130 ating with said supporting member and the first named member by which may be indicated different transverse diameters of said tapering portion, substantially as set forth.

6. in a micrometer, a plug having a relatively thin flat tapering end portion, an externally threaded sleeve revoluble on said plug, a hollow cylindrical member having threaded connection with said sleeve and in which the plug is longitudinally slidable and having a longitudinal row of peripheral graduations, a member attached to said cylindrical member and provided with a slot through which said tapering portion eX- tends and is longitudinally slioably fitted and member movable with said sleeve and arranged to indicate said graduations, substantially as set forth.

7. In a micrometer, an elongated measuring member having a relatively thin flat tapering end portion, a hollow cylindrical member in which the measuring member is longitudinally movable and having a longitudinal row of graduations representing different transverse diameters of said tapering portion, means movable with said measuring member for registering with said graduations, and a member attached to said cylindrical member and having a slot in which said tapering portion is longitudinally slidably fitted and through which said tapering portion is adapted to extend, substantially as set forth.

8. In a micrometer, an elongated measuring member having a relatively thin fiat tapering end portion, a hollow cylindrical member in which the measuring member is longitudinally movable and having a l0ngitudi nal row of graduations representing respectively different transverse diameters of said tapering portion, indicating means movable with said measuring member and cooperating with said graduations, and a member having screw thread connection with said graduated member and having a slot through which said tapering portion is adapted to extend and in which it is longitudinally slidable, substantially as set forth.

In testimony whereof I have signed my name to this specification.

LLOYD G. ILIFF. 

